Event based occupancy detection

ABSTRACT

An improved occupancy based, object oriented, load management system using anonymous, stateless messaging to communicate real and simulated occupancy detection events between control objects hosted by a plethora of control devices.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates primarily to occupancy based loadmanagement systems for lighting, plug-load, and similar loads beingmanaged to reduce energy use or to provide response to emergency andsecurity inputs.

2. Description of the Related Art

Prior art occupancy based load management is based on onymous or namedcommunication between an occupancy detection sensor and a zonecontroller. These two components determine if a zone is occupied andthen modulate a connected electrical load accordingly. The basicoperation of this communication was worked out over 20 years ago. Asensor detects motion, sound or another proxy for human presence andthen communicates that status to a load controller that hastraditionally been a relay.

Conventional Occupancy logic switches on the connected load when a zonebecomes occupied and switches off that load when the zone becomesunoccupied. With more recent Vacancy logic the auto-off step is retainedbut the load is turned on manually. In actual operation, occupancydetection is often spotty so a delay timer is added to smooth out theprocess by creating a window of time during which the detected occupancywill reset the delay timer to keep the lights on.

The above process can also be described in terms of states. The zonestarts in an unoccupied or idle state and changes to an active statewhen occupancy is detected. If the sensor is configured for occupancylogic there is an action associated with the state change to switch onthe connected load. If vacancy logic is being used the load is assumedto be turned on manually. The active state continues until the activestate timer times out. This timer is set to its timeout period each timethat an occupancy proxy event is detected. If no proxy event is detectedthe timer times out and the auto-off process begins.

Multi-Sensor Operation—When zones are too large for a single sensor,multiple sensors are typically used to cover the space. The conventionalsolution has been to parallel wire multiple stand-alone sensors to asingle load controller. When any one sensor detects presence and trips(changes from its idle to active state) it closes an internal switchwhich activates the controller. If the controller is a relay, the relaysolenoid activates which then closes the relay and switches on theconnected load. As more sensors detect occupancy, they also trip but noadditional action occurs because the zone is already in the activestate. However, as the zone becomes unoccupied all the parallel wiredsensors must return to their idle sate before the zone becomes fullyunoccupied and the electrical load is allowed to turn off. In Booleanlogic terms the on function is an OR gate and the off function is an ANDgate.

The parallel wired approach has worked well but is cumbersome andrestrictive. Parallel wired sensors require long cable runs and 3-wirepolarized connections that can be miss-wired. They also have limitedcapacity due to available power of the controller. Power limits can beaddressed by power boosters but in larger rooms and corridors there islittle that can be done about long cable runs. Additionally, addingadditional sensors or making other changes to the zone operation requirerewiring and each sensor adjustment must be made manually at eachsensor. In small applications these limitations are likely notsignificant but a larger buildings the act individually maintaininghundreds and even thousands of sensors can be overwhelming.

Networking sensors together has the potential to addresses theseproblems. However, as occupancy sensors have been adapted to networking,much of their operation has not changed. Prior art networked sensorscontinue to operate as independent devices and act as if they wereparallel wired. In order to make this work the zone controller must knowhow many sensors are covering a zone and must then keep track of thestate of each sensor. This is done with an onymous communication fromeach sensor that is sent each time the sensor changes state.

To avoid these problems U.S. Pat. No. 8,009,042 B2 limits the number ofsensors allowing the sensors and zone controller to be preconfigured.Zones with a variable number of sensors can be supported but only byoffering products that are preconfigured for varying number of sensorsor by providing some form of field configuration to set up the zone fora fixed number of sensors.

U.S. Pat. No. 8,009,042 B2 also acknowledges another problem with priorart networked sensors wherein the loss of a any sensor in the activestate will prevent the virtual circuit from clearing and returning tothe unoccupied state. U.S. Pat. No. 8,009,042 B2 addresses problem byadding a heartbeat function to detect any missing sensors but thefundamental problem caused by state-based logic remains.

Thus, what is needed is a new approach. Advanced lighting controlsystems with sophisticated interactive occupancy detection, daylighting,and user control are becoming increasingly common due to their capacityto significantly reduce energy use and to deliver an enhanced workenvironment. However, as these systems become larger and more complex sotoo do the associated problems of installation, operation, maintenance,testing, and emergency operation. Networked systems have the potentialto meet these new demands but the systems need to be flexible andadaptable enough to fully cover all spaces with minimal installation andbe robust enough to detect problems and continue working even whensensors fail or are added, removed, or reconfigured.

SUMMARY OF THE INVENTION

The present invention uses stateless sensors and anonymous communicationto create a more robust and functional lighting control system that iseasier to configure, supports an unlimited number of sensors, allowssensors to added or removed, and supports remote operation, testing, andmanagement.

Where known prior art systems use multiple, state-based, independentsensors the present invention introduces an improved Master-Scout eventreporting concept wherein multiple Scout sensors send anonymous,stateless, event reports to a single Master zone controller. When anoccupancy event is detected, Scout sensors report only that event. Eachtrip, regardless of source, has the potential to initiate or sustain theactive state of the Master controller. As a zone becomes unoccupied,trip reports stop being sent allowing the Master control to time out andreturn to the idle state. Loss or addition of sensors does not affectoperation because the Master does not need to know of or trackindividual sensors.

Additionally, without the need to track individual sensors systemfunctionality is greatly increased. The present invention allows tripreports to be created and sent by plethora of sources—not just otheroccupancy sesnors—including momentary contact buttons, user controls,personal computers, and other building automation systems to includefire alarm, security, and access control.

Vacancy Logic—Vacancy logic with manual-on and auto-off load control hasmany advantages. Besides being more energy efficient, it is alsoinherently more reliable and intuitive for most applications. Becausecontrol systems cannot read minds, determining a user's actual intent isnot possible. The best we can do is to use a proxy like motion or soundthat detects physical behavior. However, with vacancy logic there is nouncertainty. If a user wants the lights or other loads on then theymanually turn them on. Released from their conventional auto-onfunction, occupancy sensors no longer need to cover all entrances into azone. This allows sensors to be specified and located to optimizecoverage of high value areas like desks or the center of a conferenceroom. However, there is a problem. If a user turns on lights withoutsubsequently tripping the occupancy sensor the auto-off sequence is notinitiated and the lights will not turn off. The present invention solvesthis problem by allowing the the wall control to not only turn on lightsbut also send a trip report to the Master to initiate the auto-offsequence; whereby, lights will always turn off even if the occupancysensor is itself is not physically tripped.

Group Addressing—Another feature of the present invention is multiplegroup addressing. In addition to each zone having a unique zone or groupaddress the present invention allows each Master zone controller torespond to broadcast commands and additional group commands. Thiscapacity means that groups of Master controls can be created to covernot only a single room but also other larger control zones to includework areas, building floors, whole buildings, and even whole campuses.Applications include testing and system-wide response to emergencyoperation.

Testing and Documentation—In large and even smaller buildings testingand ongoing maintenance of systems can be difficult and expensive.Individual sensors can be locally tripped of course but even if thebasic cost of getting to a room is ignored some rooms may beinaccessible and systematic field testing and documentation areinherently problematic. The present invention resolves this problem byproviding the capacity to trip individual and groups of sensorsremotely. Coupled with the ability of some networked lighting controlsystems to monitor the status of lighting objects, the system can betripped and then queried to verify response. After a designated timeout,the system can again be queried to verify the expected response. Withappropriate software the results of this type of test can also becaptured to produce initial and ongoing system performance verificationand documentation.

Interface to Other Systems—Emergency response is another criticalfunction. Many known prior art systems do have the ability to turnlights on and off in response to emergency events but this can beintrusive and it can be difficult to know when to turn lights off afterthe emergency event is over. The present invention resolves this problemby allowing an emergency event to trip the Master zone controllers. Ifoccupancy logic is being used the lights will turn on. If vacancy logicis being used tripping and turning the lights on can happenconcurrently. In both cases the auto-off cycle will be initiatedallowing unoccupied zones to respond to local conditions so thatoccupied zones stay on and unoccupied zones turn off. This capacityimproves overall performance by assuring the required emergency responsewhile reducing energy use and providing more intuitive operation.

DALI Auto-on Function—As part of its initial and emergency responseoperation, the DALI protocol requires that DALI ballasts turn on eachtime lighting power is cycled. In the event of a power outage longerthan about 500 ms all DALI controlled lights will turn on. This can be aproblem if the power cycle event happens late at night or at anothertime when the building is otherwise unoccupied. The present inventionresolves this problem by providing an optional function that tripsMaster zone controllers to begin the auto-off sequence each time theDALI control power is cycled. If a particular room is occupied thelights stay on, otherwise, the zone times out and turns off.

Switch Timers—Delay-off switches are another embodiment of the presentinvention. In some areas the use of occupancy sensors may not bepossible or economically justified. A typical application is unfinishedspace. Building codes typically require lighting and some form ofauto-off control but placing occupancy sensors throughout the space maybe unwarranted. In these and similar cases a delay timer can be used.Known prior art systems can support this kind of function with a simpletwist timer but coordinating this function in rooms with multipleentrances can be problematic. Central relay panels can also be used butin addition to the cost of relay panels and home-run wiring thisapplication typically requires occupancy sensors.

The present invention resolves this problem by allowing networkedswitches at each entrance to act as occupancy sensors. One switch isconfigured for Master control and occupancy logic while the others areset up as Scouts. When an on-button is pressed, a trip message is sentto the Master controller to turn lights on and initiate the auto-offsequence. Pressing any on-button in the space acts like a normaloccupancy sensor and resets the occupancy delay timer to sustain theactive, lights-on state. When the space becomes unoccupied the delaytimer times out and turns off the lights. This approach has theadditional advantage of being able to link the space into the lightingcontrol system to provide a standard full function occupancy interfacethat includes adjustable occupancy delay time, remote control andmonitoring, and a warning period that blinks or dims the lights beforeturning off.

Multiple Sensor Technologies—Occupancy detection with multiple sensortechnologies is another application of the present invention. Multitechnology occupancy detection is well established in prior artapplications but in addition to the same problems of onymouscommunication and state tracking described above multiple technologysensors have an additional problem that occurs when sensor outputs mustbe treated differently. The problem occurs when different sensortechnologies are used to cover a space. rior art wired systems are ableto side step the problem by resolving all sensor inputs to a singlestate change and switch closure. However, some sensor combinations likePIR and audio range acoustic may require that sensor events be treateddifferently. The present invention allows for this by enhancing itscommunication protocol to include multiple message types that identifysensor trips by their technology type. With this additional informationthe Master zone controller can then process each type of sensor tripseparately in order to provide complete multi-sensor, multi technologybenefits.

Other features and advantages of the present invention will becomeapparent from the following description of the invention that referencesthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1—System Deployment is a simplified system deployment overview of alighting control system with a variety of actors and actor surrogateshaving input into the system where actors are actual persons and actorsurrogates are items like sensors and scheduling means that operate onthe system through algorithms that embody actor intensions.

FIG. 2—Zone Control Static Diagram is a simplified static diagram ofzone control showing the interaction of objects within the system.

FIG. 3—Button Control Object Item 216 is a simplified state diagram of abutton control object.

FIG. 4—Scout Control Object Item 218 is the state diagram of a Scoutcontrol object.

FIG. 5—Master Control Object Item 220 is the state diagram of a Mastercontrol object.

FIG. 6—Switch Timer Deployment Diagram is a simplified deploymentdiagram of a switch timer embodiment.

FIG. 7—Switch Timer Static Model is a simplified static diagram of thesame switch timer diagramed in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

The foregoing summary, as well as the following detailed description ofthe preferred embodiments, is better understood when read in conjunctionwith the appended drawings. For the purposes of illustrating theinvention, there is shown in the drawings an embodiment that ispresently preferred, in which like numerals represent similar partsthrough the several views of the drawings, it being understood, however,that the invention is not limited to the specific methods andembodiments disclosed.

FIG. 1—System Deployment is a simplified system deployment diagram ofthe preferred embodiment of the present invention showing the primaryphysical components. All of these components are linked together via acommon communication network which is a combination of a fast Ethernetbackbone network 124 and a plethora of smaller, slower local DALInetworks 126 connected through a plethora of network gateways 128. Eachof these components are called network nodes or just nodes and have thecapacity to communicate with the network and to store and run computerinstructions. Computer instructions that run on these nodes are bundledtogether into discrete firmware packages called objects. Each object isan instance of a set of computer instructions called a class and eachobject is made unique by property settings and a unique identification.

Master and Scout devices 110 and 112 are both nodes and sensorplatforms. They may be physically identical but configured to operatedifferently. Scouts have an activated Scout object 218 and perform thejob of detecting and reporting occupancy events to the Master object 220via the DALI network 126. User controls 116 are nodes that connect tothe DALI network 126 and have the capacity to host objects includingbuttons 216, Scout 218, and Master 220 objects. DALI loads 114 are nodesthat host DALI objects and have means of regulating an electrical load.Examples of DALI loads include dimming ballasts, incandescent dimmers,DALI to 0-10 v gateways, and digital outputs connected to relays. Thesedevices may be stand alone or included with other nodes such as thepreferred embodiment where all Scouts and Master nodes include a digitaloutput that can drive a self powered relay or communicate with otherdevices and systems.

Occupant workstations 120, laptops 118, and a system controller/server122 can also host control objects and communicate with Scout 218, Master220, and button 216 objects via the network.

FIG. 2—Zone Control Static Diagram is a simplified static diagram of asingle zone that shows the relationship between the control objects. Atypical zone has one Master control object 220 and any number of supportobjects consisting of buttons 216, Scouts 218, and loads 214.Additionally, there may be any number of external objects and supportprograms 212 that can also provide control messages. Master objects 220process both local and remote sensor input in order to determine theoccupied status or state of a zone and then use this information toregulate electrical loads via instructions to the DALI load objects 214.

Objects interact to determine the occupied state of a zone and regulatethe zone load by sending and receiving messages. These messages arelabeled M1 through M6 and support two sensor types. A first sensor typeof the preferred embodiment is a PIR (Passive Infrared) sensor thatdetects motion by monitoring changes in infrared energy. A second sensortype of the preferred embodiment is a PAR (Passive Audio Range) sensorthat detects occupancy by listening for non-periodic sound. When a Scoutdetects an event it informs the Master by sending M1 messages for PIRevents and M2 messages for PAR events.

The job of the M1 and M2 messages is to inform the Master control objectthat an occupancy event has occurred. These events may have been createdby actual sensors or alternatively by some other event like a buttonpress. Regardless of actual source, the Master control object treats allM1 and M2 messages the same without regard to origin or state allowingthe messages to be both anonymous and stateless.

A third message type M3 may be sent to the load control object. In thepreferred embodiment this message format conforms to the open sourceDALI protocol and may be any command that instructs the DALI loadcontrol object to regulate an electrical load. On-commands includegoto-level, goto-scene, goto-minimum, and goto-maximum all of whichregulate loads via various actuators including relays and dimmingballasts. These commands may be generated by a variety of sourcesincluding user interface objects 216, Master controller objects 220, andother objects 212.

A fourth and fifth message type, M4 and M5, are also supported. Like M1and M2, these messages are anonymous and stateless and are tagged asbeing created by a first and second sensor type. However, these messagesare only processed by Scout sensors in order to simulate a Scout tripwhich in-turn generates an M1 or M2 message that is sent to the Mastercontroller. In this way Scout sensors can be remotely tripped while themonitoring the Master controller in order to verify that the Scouts areconfigured and operating properly.

A sixth message type, M6, is also supported which operates like M4 andM5 but simulates the physical event of pressing a button. This messagemay be used to test the configuration and operation of user interfacesas well as allowing user interface buttons to be remotely operated toprovide expanded user and automatic control.

FIG. 3—Button Control Object Item 216 is a simplified state diagram of abutton control object 216 configured for the preferred embodiment ofvacancy logic. The button has one state, idle 314. When the button ispressed it creates an event 312 and at set of actions 216. The firstaction is to send an M3 message to Load object 214 to turn lights on.The second action 216 is to send an M1 or M2 message to the Mastercontrol object 220 to initiate the auto-off sequence.

FIG. 4—Scout Control Object Item 218 is a simplified state diagram ofthe Scout control object 218 configured for the preferred embodiment oftwo sensor technologies 414 and 416 and a transmit delay timer 412. Inthis embodiment the first sensor technology is a Passive Infrared (PIR)motion sensor and the second is a Passive Audio Range (PAR) acousticsensor. PIR sensors have excellent line-of-sight characteristic butcannot “see” through barriers. PAR sensors detect sharp changes inaudio-range sound that allows them to “hear” both directly and aroundbarriers. The two technologies complement each other to provide a levelof detection superior to what either can do by itself. However, the twosensor types must also be processed differently to assure optimalperformance. The embodiment also incorporates some logic to reducenetwork traffic by introducing a delay between trip reports and toassure that PIR trips are always reported even if the Scout has beenpreviously tripped by the PAR sensor.

The state diagram begins with the sensor in its idle state 410. Wheneither sensor trips or a M4 or M5 trip message is received, the Scoutobject changes from its idle state 414 to the delay state 412. If thetrip is from a first sensor 414 or a M4 trip message is received an M1trip report is sent followed by a second action to set the first sensortrip flag 414. If the trip is from a second sensor 416 or an M5 tripmessage is received the M2 trip report is sent. Either type of tripstarts the transmit delay timer (XDT) 418 before entering the transmitdelay state 412. However, if the trip came from the second sensor 416the Scout will still respond to a first sensor trip 420 and send an M1trip report. When the XDT times out 422, all flags are cleared and theScout object 218 returns to its idle state 410 ready to process anothertrip event.

FIG. 5—Master Control Object Item 220 is a simplified state diagram ofthe Master control object 220 configured for the preferred embodiment ofvacancy logic and first and second PIR and PAR sensors. The embodimentdemonstrates the advantage of being able to process the two sensortechnologies differently. PAR sensors are more susceptible to falsetripping so the Master typically only allows a PIT trip to initiate achange from the idle state 510 to active state 514. However, once in theactive state 514, acoustic trips are accepted but only for a limitedtime which is reset each time a PIR trip is detected 530 and 528B.

The state diagram begins with the Master object 220 in its idle state510. When the first sensor trips or an M1 message is received 516, theobject 220 moves from its idle state 510 to its active state 514 whilesetting the AOT (Acoustic Override Timer) 520. Upon entry into theactive state 514 the AST (Active State Timer) is set. While in theactive state 514, a trip of either a first 522 or second sensor 530 orthe receipt of either an M1 or M2 messages from a Scout or other sourceresets the AST to sustain the active state 514. However, the two sensorsand their associated M1 and M2 messages are not treated the same. Afirst sensor trip has the additional job of setting the AOT 520 while asecond sensor trip 522 only resets the AST 514.

The active state is sustained until the either the AST 524 or the AOT534 times out or a DALI command to turn off the designated zone isdetected 538. In the preferred embodiment both the AST 524 and AOT 524timeout events move the object 220 to an interim warning state 512however an AOT event 534 first disables any further PAR trips 534. Uponentry into the warning state 512 a sequence of actions occurs. First,commands are sent to the DALI load control objects 214 to capture theircurrent setting to their scene 15 memory. Secondly, commands are sent tothe DALI load control objects 214 to either dim or turn off depending onthe configuration settings followed by a final internal command to setthe WST (Warning State Timer) to its timeout value.

The warning state is sustained until a sensor trip event 528 occurs, theWST times out 536, or a DALI off command 538 is detected. A sensor tripor trip message 528 causes the object 220 to return to the active state514 after first sending a DALI command to return to scene 15 values 528.If the trip originates from the first sensor or an M1 trip message isreceived 518 then the AOT 520 is also set. If a trip event is notdetected the Master object returns to its idle state 510. Entry into theidle state clears all timers and flags whereupon the object 220 is readyto receive another trip event.

Master controllers configured for automatic-on operate the same exceptfor incorporating an action to send an on command to the DALI loadobject 214 during the idle to active state transition 516.

FIG. 6—Switch Timer Deployment Diagram is a simplified deploymentdiagram of a three station 116 switch timer system wherein a singleelectrical load is regulated by a relay 614. In this embodiment thereare no presence sensors. Rather, users entering a space manually turn onthe lights from any one of the three stations by pressing an on-button.Lights are turned off by manually pressing the off button at any usercontrol or after a timeout period has passed.

The three stations 116A, 116B, 116C are all connected to a DALI network126 and each station is configured with two buttons, one for on and onefor off. In addition to user buttons one of the stations also hosts aMaster control object 220. Except for the physical difference of nothave any occupancy sensors, the embodiment operates the same and usesthe same Master Control Object logic detailed in FIG. 5. This is asignificant advantage over prior art system as it allows this specialapplication to be configured, operated, and maintained using the sameuser interfaces, concepts, and equipment as systems that have occupancysensors.

FIG. 7—Switch Timer Static Model is a simplified static diagram of thesame switch timer embodiment diagramed in FIG. 6. In this embodiment anon button press event at any one of the buttons 216A, 216B, 216Cinitiates the transmittal of a M1 type message which informs the Masterthat a first sensor type trip has occurred. Upon receiving the M1message, the Master processes it as it would any other first sensorevent as diagramed by FIG. 5. In this embodiment the Master occupancyobject is additionally configured with auto-on logic wherein an additionaction is added to the Trip-PIR sequence 516 to send a DALI on commandor close a load control relay directly.

If the Master is in its rest state 510 when the M1 message is receivedthe lights turn on and the Master object transitions to its Active state514. Additional M1 messages from any of a plethora of similarlyconfigured on-buttons simulate a first sensor trip 522 to reset the ASTtimer and hold the Master in its Active state 514. When lights areturned off by any of a plethora of off-buttons or other objects a DALIoff command is sent to the DALI load control object and detected by theMaster object 538. The Master then returns to its rest state and clearsall timers and flags 510. If no DALI off command is detected, the ASTtimer times out 524 initiating a change to the Warning state 512 withadditional actions as diagram in FIG. 5. The advantage of thisembodiment over prior art is its flexibility, consistency, andopen-ended nature. A field installer using the system can implement itwith the same standard user controls used for other controlapplications. Operation is solely determined by configuration which istypically implemented by selecting and running configuration scripts.The scripts determine whether the buttons are single or alternativeaction and the zone to be controlled. Configuration also establisheswhich button will be the Master and which will be Scouts. Trip eventsare anonymous and stateless and the Master keeps no record of tripsource or state so trip events can be generated by any of a plethora ofdiverse sources which can be added or removed without affectingoperation or requiring re-wiring or re-configuration.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. A method for determining the occupied state of adesignated zone by using a computer processor to analyze anonymous eventmessages received from a plurality of sources comprising the steps of:a. listening for occupancy event messages addressed to a specific zone,b. processing said messages using a computer algorithm to determine ormaintain the occupied state of said zone, whereby an occupied state isdetermined by processing event messages received from a plurality ofanonymous sources and applications to include controlling electric loadsand providing occupied state information to other security, accesscontrol, and other systems and applications.
 2. The occupancy statedetermination method of claim 1 said anonymous event messages are alsoasynchronous.
 3. The occupancy state determination method of claim 1wherein said occupied state is determined by processing event messagesreceived from a plurality of anonymous sources for application toinclude controlling electric loads and providing occupied stateinformation to other security, access control, and other systems andapplications.
 4. An occupancy detection system comprising: a. a mastercontroller with the means to send and receive messages and to processoccupancy detection event messages in accordance with a predefinedcomputer algorithm, b. a plurality of scout devices with the means tosend said messages in response to real or simulated occupancy detectionevents, and c. a communications network with the means to transmit saidmessages, whereby robust, flexible networks of a plurality of sensorsand other scout devices can be built where the addition or loss of scoutdevices does not affect operation.
 5. The occupancy detection system ofclaim 4 wherein said master controller includes the means to controlelectrical loads directly or via transmitted messages,
 6. The occupancydetection system of claim 4 wherein said occupancy detection eventmessages contain additional information to include the type of occupancyevent, whereby said master controller can take into account the sourceof an occupancy event when processing an event message. Applicationsinclude dual technology systems where different types of sensors likePIR and acoustic require different processing.
 7. The occupancydetection system of claim 4 wherein said master controller algorithmincludes a time delay function to prevent acoustic sensor detectionevents from maintaining the occupied state without periodic verificationof a MR or similar line-of-sight sensor.
 8. The occupancy detectionsystem of claim 4 wherein said master controller is bundle of computerinstructions called an object that can be hosted by a computer processorinside or outside of said zone and within devices that include sensors,relays drivers, and other input and output devices.
 9. The occupancydetection system of claim 4 wherein said communications network consistsof a wired or wireless medium and protocol a communications protocol toinclude Ethernet, DAM, and Zigbee.
 10. The occupancy detection system ofclaim 4 wherein event messages may originate locally from within thecontrolled zone, remotely from outside the controlled zone, or fromwithin the same physical device hosting the Master control object. 11.The occupancy detection system of claim 4 wherein said occupancy eventmessages may be produced by a variety of changing conditions includingmotion, sound, user actions that include operation of momentary contactbuttons, keyboards, mice, and graphical user interfaces, and by usersurrogates that include scheduled events and interfaces with otherbuilding control systems. whereby the occupied state and the functionsit controls can be controlled, tested, and managed based upon a varietyof detected, simulated, and inferred occupancy events.
 12. The occupancydetection system of claim 4 wherein a method is added to force saidmaster controller to return its idle state in the event that theelectric load in its control zone is turned off by any means comprisingthe steps of: a. listening for off type commands addressed to the loadcontrol zone, and b. clearing all timers and flags and then returningthe master controller to its idle state, whereby it is assured that themaster controller stays synchronized with the lighting state, auto-onzones which are inadvertently turned off while occupied will turn backon immediately as soon as occupancy is detected, and occupancy sensorswith auto-on logic can be field tested by sending an off command to thezone to reset all sensors to their idle state.
 13. The occupancydetection system of claim 4 wherein a warning period is added to themaster controller comprising the steps of: c. changing from the activeto warning state upon time out of the active state delay timer precludedby a first action of sending a message to the zone load control objectsto capture and store their present light level to a designated scenevalue followed by a second action of sending a message to said zonecontrol objects to either dim or turn off followed by a third action ofsetting the warning state delay timer to its timeout value, and d.changing from the warning to active state upon receiving an occupancyevent message precluded by a fourth action of sending a message to thezone load control objects to either return to the previously capturedscene or return to a fixed light level, and e. changing from the warningto idle state upon the timeout of the warning state delay timer, wherebyoccupants in zones with vacancy logic are given the opportunity toreturn to the active state and restore the light level before lights thelight level must be reactivated manually, and whereby the potentialsafety hazard of requiring an occupant to navigate through a darkenedroom in order to reach a lighting control is avoided.
 14. The occupancydetection system of claim 4 wherein said scout devices include a timedelay method to reduce network traffic by limiting the frequency ofoccupancy event transmissions comprising the steps of: a. changing fromthe idle to active state upon an occupancy trip event by either a firstor second occupancy sensor, b. transmitting a first or second occupancyevent message, c. setting the active state timer, d. ignoring additionaloccupancy trip events while in said active state, e. clearing all memoryflags and returning to the idle state when the active state timer timesout.
 15. The network traffic reduction method of claim 12 wherein stepsare added to assure that a higher priority occupancy event created bysensor 1 is immediately transmitted at least once per transmit delayperiod even if said scout is already in the transmit delay statecomprising the steps of: a. setting a memory flag each time a firstsensor occupancy transmission event occurs, b. sending a first sensoroccupancy event message if said memory flag is not set regardless of thescout state. whereby it is assured that automatic-on systems that canonly be tripped by a FIR trip event always react immediately even if aprevious acoustic trip has put the scout into its network trafficreduction state.